# Patent

## Title
Vented positioner and spacer and method of use

## Abstract

Disclosed is a device positioner for guiding and positioning energy delivery devices during a surgical procedure. The energy delivery device positioner includes a body, a plurality of legs coupled to the body and a plurality of ribs connected to the body. The body includes a body facing surface and a plurality of device positioner apertures defined therein. The device positioner apertures are configured to receive an energy delivery device therethrough. The plurality of legs includes at least one foot extending beyond the patient facing surface of the body with the distal end of the foot configured to contact patient tissue and elevate the patient facing surface of the body such that the patient facing surface is spaced away from patient tissue. The plurality of ribs form one or more air flow aperture.

## Background
BACKGROUND
1. Technical Field
The present disclosure relates to apparatus, systems and methods for providing energy to biological tissue and, more particularly, to apparatuses, systems and methods for precise placement of energy delivery devices in a surgical procedure.
2. Background of Related Art
Energy-based tissue treatment is well known in the art. Various types of energy (e.g., electrical, ultrasonic, microwave, cryogenic, thermal, laser, etc.) are applied to tissue to achieve a desired result. Electrosurgery involves application of high radio frequency electrical current to a surgical site to cut, ablate, coagulate or seal tissue. In monopolar electrosurgery, a source or active electrode delivers radio frequency energy from the electrosurgical generator to the tissue and a return electrode carries the current back to the generator. In monopolar electrosurgery, the source electrode is typically part of the surgical instrument held by the surgeon and applied to the tissue to be treated and a patient return electrode is placed remotely from the active electrode to carry the current back to the generator. In bipolar electrosurgery, the active and return electrodes are placed in close proximity to each other, e.g., at the surgical site, and electrosurgical currents are passed therebetween. In microwave electrosurgery, the antenna of the microwave energy delivery device generates electromagnetic fields in the adjacent tissue without the generation of electrosurgical currents between an active electrode and a return electrode as discussed hereinabove.
Radio frequency energy may be delivered to targeted tissue in an ablation procedure by electrosurgical probes or by an electrosurgical antenna. In the case of tissue ablation using electrosurgical probes, electrode pairs are positioned in the surgical site to delivery high frequency electrosurgical currents between the pairs of active (+) and return (−) electrodes. An active (+) electrode and a return (−) electrode may be positioned in a spaced apart relationship on the shaft of an electrosurgical probe such that electrosurgical currents are passed along, or parallel to the shaft.
Alternatively, a first probe may function as an active (+) electrode and a second probe may function as a return (−) electrode. The first and second probes are positioned in a spaced apart relationship relative to each other such that electrosurgical currents are passed between the active (+) and return (−) electrodes resulting in the ablation of tissue positioned between the two probes. As such, the ablation region is defined by the spacing between the active (+) and return (−) electrodes and heating of tissue is typically confined therebetween. During ablation, current pathways in tissue between the active (+) and return (−) electrode produces localized heating between the two probes.
Radio frequency energy in a microwave frequency range may be delivered to a targeted tissue by a microwave energy delivery device with a microwave antenna on the distal tip. The antenna of the microwave energy delivery device, when provided with a microwave energy signal, generates electromagnetic fields in the adjacent tissue without the generation of electrosurgical currents between an active electrode and a return electrode as discussed hereinabove.
While the ablation region produced by ablation probes is defined by the current path between the electrodes, the ablation region (shape and area) produced by a microwave energy delivery device is defined by the type of antenna, the frequency of the microwave energy signal and the power level of the microwave energy signal. For example, an ablation region generated by a microwave energy delivery device may be symmetric about the tip and shaft of the microwave energy delivery device, directed to only one side of the shaft or if the antenna is unchoked, the ablation region may include a “tail” portion that extends proximally up the elongated shaft of the microwave energy delivery device.
Unlike radio frequency probes, microwave energy delivery devices need not be configured to interact with each other. In fact, microwave energy delivery devices typically do not interact since any interaction would be due to the intermingling of the electromagnetic fields generated by the two devices i.e., the two devices placed in close proximity may result in the overlapping of electromagnetic fields generated by each microwave energy delivery device. The overlapping electromagnetic fields may result in unpredictable results as the electromagnetic fields may cancel each other (resulting in no heating), the electromagnetic fields may, combine (resulting in the generation of pockets of extremely high current densities) or any combination thereof. As such, controlling the interaction between microwave energy delivery devices becomes even more complicated when the surgical procedures requires the insertion of a plurality of microwave energy delivery devices.
The unpredictable nature of the overlapping electromagnetic fields can be overcome by precisely placing the microwave energy delivery devices in a target tissue. The present disclosure describes apparatuses, systems and methods for precise placement of microwave energy delivery devices in a surgical procedure.
SUMMARY
The present disclosure describes an apparatuses, systems and methods for precise placement of microwave energy deliver devices in a surgical procedure. The microwave energy delivery device positioner includes a body, a plurality of legs operably coupled to the body and a plurality of ribs connected to the body. The body includes a body facing surface and a plurality of device positioner apertures defined therein. The device positioner apertures are configured to receive a microwave energy delivery device therethrough. The plurality of legs includes one or more feet extending beyond the patient facing surface of the body with the distal end of the feet being configured to contact patient tissue and elevate the patient facing surface of the body such that the patient facing surface is spaced away from patient tissue. The plurality of ribs form at least one air flow aperture.
The plurality of device positioner apertures further includes a first set of device positioner apertures defined therein and a second set of device positioner apertures defined therein. The first and second sets of device positioner apertures may include three apertures having radial centers equally spaced relative to one another. At least one radial center of the second set of device positioner apertures may be positioned about midway between two of the first set of device positioner apertures.
In one embodiment the plurality of legs may be substantially equal in length and may elevate the tissue facing surface of the body at least 1⁄2 inch relative to body tissue. The plurality of ribs may be configured to provide structural rigidity and may form at least three air flow, apertures defined therefrom.
In another embodiment the plurality of device positioner apertures formed by the body may be substantially parallel such that the microwave energy delivery devices inserted through the plurality of device positioner apertures are maintained in a substantially parallel orientation.
The present disclosure also discloses an electrosurgical ablation system including a microwave energy source, a microwave positioner of the present disclosure and a plurality of tissue penetrating microwave energy delivery devices with a microwave antenna at the distal tip thereof, the antenna configured to receive a microwave energy signal from the microwave energy source and to radiate microwave energy therefrom. The microwave positioner includes a body, defining a plurality, of device positioner apertures and a patient facing surface, a plurality of legs operably coupled to the body and a plurality of ribs connected to the body and forming at least one air flow apertures. The legs include one or more feet extending beyond the patient facing surface of the body, the feet being configured to contact patient tissue. The device positioner apertures formed by the body are configured to receive tissue penetrating microwave devices therethrough. The feet and legs elevate the patient facing surface of the body such that the patient facing surface is spaced away from patient tissue.
In one embodiment the plurality of device positioner apertures are configured to guide the tissue penetrating microwave devices. The plurality of device positioner apertures may further include a first and a second set of device positioner apertures defined therein. The first set of device positioner apertures may include three apertures having radial centers equally spaced relative to one another. The second set of device positioner apertures may include radial centers equally spaced relative to one another with at least one radial center being positioned about midway between two of the first set of device positioner apertures.
In another embodiment the plurality of legs may include three feet substantially equal in length that elevate the tissue facing surface of the body at least 1⁄2 inch relative to body tissue.
The present disclosure also includes a method for positioning a plurality of tissue penetrating microwave energy delivery devices, the method including the steps of: positioning a microwave positioner on patient tissue adjacent a target tissue; inserting a first tissue penetrating microwave energy delivery device, including a shaft with an antenna on the distal end thereof, through a first device positioning aperture formed in the body of the microwave positioner, the first device positioning aperture configured to guide the first tissue penetrating microwave energy delivery device; advancing the antenna of the first tissue penetrating microwave energy delivery device to a target tissue; inserting a subsequent tissue penetrating microwave energy delivery device through a second device positioning aperture formed in the body of the microwave positioner; and advancing the subsequent tissue penetrating microwave energy delivery device antenna to a target tissue, wherein the elongated shaft of the first tissue penetrating microwave energy delivery device is maintained in a substantially parallel orientation to the elongated shaft of the subsequent tissue penetrating microwave energy delivery device.
In one embodiment the microwave positioner includes a body having a plurality of device positioner apertures defined therein. The body includes a patient facing surface, a plurality of legs operably coupled to the body including one or more feet extending beyond the patient facing surface of the body the distal ends of the feet are configured to contact patient tissue. A plurality of ribs connect to the body and form at least one air flow aperture. The plurality of device positioner apertures formed by the body are configured to receive a microwave energy delivery, device therethrough and the plurality of legs elevate the patient facing surface of the body such that the patient facing surface is spaced away from patient tissue.
The method may further include the step of delivering microwave energy to the target tissue. The at least one air flow aperture may facilitate cooling of the first tissue penetrating microwave energy delivery device.



BRIEF DESCRIPTION OF THE DRAWINGS
The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view of a microwave positioner, in accordance with an embodiment of the present disclosure, positioning three microwave energy delivery devices in a first configuration;
FIG. 2 is a perspective view from the underside of the microwave positioner of FIG. 1, illustrating airflow passageways through the microwave positioner and positioning three microwave energy delivery devices in a second configuration;
FIG. 3 is a top view of the microwave positioner of FIG. 1;
FIG. 4 is a perspective view of the microwave positioner of FIG. 1 and the distal antenna portions of the microwave energy delivery devices;
FIG. 5 is an illustration of a microwave energy delivery system including a microwave positioner of the present disclosure;
FIG. 6 is a perspective view of a portion of the microwave energy delivery system of FIG. 5.



DETAILED DESCRIPTION
Particular embodiments of the present disclosure will be described hereinbelow with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.
In the drawings and in the descriptions that follow, the term “proximal,” as is traditional, shall refer to the end of the instrument that is closer to the user, while the term “distal” shall refer to the end that is farther from the user. In addition, although the following description describes the present invention with respect to a microwave antenna application, the present invention may also be applicable to other energy-based applications, such as RF ablation probes, cryo probes, and the like.
FIG. 1 shows a perspective view of a microwave positioner 100 in accordance with the present disclosure. Body 110 of the microwave positioner 100 forms a plurality of legs 120a-120c and a plurality of apertures 140a-140c, 150a-150c and 130a-130d defined therein, the plurality of apertures extending longitudinally through the body. The microwave positioner 100 includes three sets of apertures, namely a plurality of first position device apertures 140a-140c, a plurality of second position device apertures 150a-150c and a plurality of airflow apertures 130a-130d. 
Legs 120a-120c position the microwave positioner 100 on the patient. As better illustrated in FIG. 2, the underside of each leg includes a foot 121a-121c that makes contact with patient tissue and aids in securing the microwave positioner 100 to the patient. Each foot 121a-121c may include an adhesive coating, non-skid cover, or a non-slip surface, or any other suitable surface or coating that aids in securing the microwave positioner 100 to the patient. It is envisioned that microwave positioner 100 may include three or more legs to secure the microwave positioner 100 to the patient.
The first position device apertures 140a-140c and the second position device apertures 150a-150c form a channel configured to guide at least a portion of the microwave energy deliver), devices 20a-20c. As illustrated in FIG. 1, the first position device apertures 140a-140c position the microwave energy delivery devices 20a-20c in close relationship with respect to each other. As illustrated in FIG. 2, the second position device apertures 150a-150c position the microwave energy delivery devices 21a-21c in a spaced apart relationship as compared to the spacing of the microwave energy delivery devices 20a-20c when inserted through the first position device apertures 140a-140c. 
Microwave positioner 100 is configured to provide a plurality of microwave energy delivery device orientations with varying spacing between each microwave energy delivery device. The spacing between the position apertures is further illustrated in FIG. 3. The portion of the body 110 that forms the first position device apertures 140a-140c positions the radial centers of the three first position device apertures 140a-140c such that the three centers form the corners of a first equilateral triangle, the sides of which are about equal to a distance D1. The portion of the body 10 that forms the second position device apertures 150a-150c positions the radial centers of the three second position device apertures 150a-150c such that the three radial centers form the corners of a second equilateral triangle, the sides of which are about equal to a distance D2. The first and second equilateral triangles are similarly arranged to a so-called “Sierpinski Triangle” where the first equilateral triangle is nested within the second equilateral triangle and D1 is necessarily less than D2.
Interior ribs 111-113 of the body 110 form the sides of the first equilateral triangle and provide structural strength to the interior of the microwave positioner 100. Interior ribs 111-113 also form the center airflow aperture 130d. 
Exterior ribs 114-119 form the sides of the second equilateral triangle and provide structural strength to the exterior of the microwave positioner 100. Outer airflow apertures 130a, 130b, 130c are formed between one of the interior ribs 111-113 and at least two of the exterior ribs 114-119. Ribs 111-119 may also include rib stiffeners, as illustrated on exterior ribs 114-119, to provide additional strength, to prevent deflection and/or to prevent the microwave positioner 100 from changing form. Ribs 111-119 are configured to maintain the structure of the microwave positioner.
Each leg 120a-120c connects to the portion of the body that forms the second position device apertures 150a-150c. The radial centers of the legs 120a-120c form a third equilateral triangle with the distance between each leg equal to D3, wherein distance D3 is greater than distance D2. As best illustrated in FIG. 4, feet 121a-121c extend from each leg 120a-120c, respectively, thereby extending the feet below the body lower surface 110a of the body 110 and the leg 120a-120c. Each foot 121a-121c extends beyond the body lower surface 110a a distance H such that the body 110 of the microwave positioner 100 is spaced away from patient tissue. In one embodiment, feet 121a-121c space the body lower surface 110a at least 1⁄2 inch away from patient tissue. In another embodiment the height H of the feet are not equal.
As illustrated in FIGS. 2 and 3, center airflow aperture 130d and outer airflow apertures 130a-130c are configured to allow heat (generated at the surface of the patient tissue) to dissipate through the microwave positioner 100a. The distal end of the feet 121a-121c contact patient tissue (not shown) and elevate the microwave positioner 10 a distance H (See FIG. 4) above patient tissue, thereby allowing air to freely flow between the lower surface 110a of the body 110, through the center airflow aperture 130d and the outer airflow apertures 130a-130c. Thermal energy generated at the surface of the patient tissue dissipates through one of the center airflow aperture 130d and the outer airflow apertures 130a-130c. Body 110 of the microwave positioner 10 may be formed from a light weight material resistance to thermal heating.
A microwave ablation procedure using a microwave positioner of the present disclosure may require the use of a plurality, of microwave energy delivery devices. In use, each of the microwave energy delivery devices is inserted through one of the apertures 140a-140c, 150a-150c formed in the body 110 of the microwave positioner 100. The microwave ablation procedure may require the use of any number and any combination of apertures 140a-140c, 150a-150c. Apertures that are not used for the insertion of microwave energy delivery devices may be used for the placement of other probes or sensors, such as, for example, one or more temperature probes or sensors.
One particular microwave ablation procedure may include the use of the three first position device apertures 140a-140c as illustrated in FIG. 1. Microwave energy delivery devices 20a, 20b, 20c are inserted in each of the first positioner device apertures 140a-140c, respectively. One or more of the second positioner device apertures 150a-150c may be used for positioning a temperature sensor or other suitable sensing device. As illustrated in FIG. 3, each of the second positioner device apertures 150a-150c is positioned a distance D4 from at least two of the first position device apertures.
With continued reference to FIG. 3, the distances D1, D2, D3 between the various apertures 140a-140c, 150a-150c formed in the body 110 of the microwave positioner 100 and the dimensions of the apertures 140c-140a, 150a-150c may vary. Distances and dimensions may be adjusted for the type of microwave energy delivery devices used in the procedure, the amount of energy delivered to the target tissue from the microwave energy delivery, devices, the number of microwave energy delivery devices required for the procedure, the number and type of sensors used to measure a tissue parameter, and specific location on the patient where the microwave positioner may be placed. In addition, there may be advantages to the have the ability to change the shape or configuration of the microwave positioner 100. Cancerous growths may be irregular in size and shape. Thus, by being able to change the shape of the microwave positioner 100, a surgeon may have more control and precision in treating the growth. For example, the surgeon may need to achieve a radius or some other shape to capture the circumference of the growth. This may be accomplished by having ribs 111-119 adjustable by having a telescopic configuration or being flexible or malleable.
Another microwave ablation procedure may require the use of three second position device apertures 150a-150c as illustrated in FIGS. 2 and 4. One or more of the first positioner device apertures 140a-140c may be used for positioning a temperature sensor or other suitable sensing device.
As illustrated in FIG. 4, the portion of the body 110 forming the first position device apertures 140a-140c and the second position device apertures 150a-150c includes a height equal to D5. As such, each apertures 140a-140c, 150a-150c, formed in the body also includes a length of D5. The aperture length D5 is sufficiently long to guide the microwave energy delivery devices 21a-21c such that the distal ends of the devices are positioned in a desirable spaced apart relationship relative to each other such that the spacing of the distal tips 51′, 52′ and 53′ are desirably spaced.
In one embodiment, the apertures 140a-140c, 150a-150c formed in the body 110 are substantially parallel to each other. The apertures 140a-140c, 150a-150c are configured to guide the microwave energy delivery devices 21a-21c such that the elongated shafts 22a-22c when inserted in the microwave positioner 10 are maintained in a substantially parallel orientation to each other. As such, the spacing S1′, S2′ and S3′ between the distal tips 23a-23c of each of the microwave energy delivery devices 21a-21c is substantially equal.
Microwave spacer may be formed with specific dimensions and tight tolerances in order to provide desirable spacing between apertures. The internal aperture dimensions may also include specific dimensions and tight tolerances in order to provide adequate guidance of the microwave energy delivery devices during insertion. For example, the microwave spacer may be formed by any suitable process, such as injection molding or casting. In addition, any suitable material may be utilized, such as plastic, ceramic, composite material, etc.
In another embodiment, the apertures 140a-140c, 150a-150c formed in the body 110 are not substantially parallel to each other. Apertures 140a-140c, 150a-150c may angle slightly inward such that the spacing 51′, 52′ and 53′ between the distal tips 23a-23c is less than the aperture spacing D1, D2, respectively (D1 and D2, as illustrated in FIG. 2 e.g., the spacing between the radial centers of the apertures 140a-140c, 150a-150c).
The portion of the body 110 that forms the first position device apertures 140a-140c positions the radial centers of the three first position device apertures 140a-140c such that the three centers approximately form the corners of a first equilateral triangle, the sides of which are about equal to a distance D1. The portion of the body 110 that forms the second position device apertures 150a-150c positions the radial centers of the three second position device apertures 150a-150c such that the three centers approximately form the corners of a second equilateral triangle, the sides of which are about equal to a distance D2. The first and second equilateral triangles are similarly arrange in a “Sierpinski Triangle” where the first equilateral triangle is nested within the second equilateral triangle and D1 is less than D2.
The embodiments described herein should not be limited to the figures and specific geometries illustrated herein as any suitable geometry and dimensioning may be used to construct a microwave positioner of the present disclosure. For example, a square-shaped microwave positioner may include four legs (one on each corner) configured to contact tissue, and a body that forms a first set of device positioning apertures (with a plurality of apertures) and a second set of device positioning apertures (with a plurality of apertures). The first and/or the second set of device positioning apertures formed by the body are nested within the square formed by the four legs. The body further includes a suitable number of ribs that connect the legs and the portion of the body that forms the apertures. The ribs also provide structural strength to the microwave positioner and form a plurality of airflow apertures through the body.
FIGS. 5 and 6 illustrate a microwave energy delivery system 20 including a microwave positioner 500, as described and illustrated in the present disclosure, and a plurality of microwave energy delivery devices 520a, 520b. The microwave energy delivery devices 520a, 520b connect to a microwave generator 590 and are configured to deliver microwave energy to a target tissue 560a. 
In use, the microwave positioner 500 is placed on the patient tissue 560 proximal to the target tissue 560a. A first microwave energy delivery device 520a is inserted through a first selected aperture 540a formed in the body 510 of the microwave positioner 500. The first selected aperture 540a guides the first microwave energy delivery device 520a while being advanced to the patient tissue 560 and inserted to the target tissue 560a. Shaft 522a, 522b of the microwave energy delivery devices 520a, 520b may include a plurality of position indicating markers 524 that indicate the depth of insertion.
A second microwave energy delivery device 520b is inserted through a second selected aperture 540b formed in the body of the 510 of the microwave positioner 500. Additional microwave energy deliver), devices and/or sensing devices may be inserted through additionally selected apertures.
A method for placing a plurality of microwave energy delivery devices and ablating tissue includes the steps of: placing the microwave positioner described in the present disclosure on a portion of patient's tissue adjacent a target tissue; inserting two or more microwave energy delivery devices through apertures formed in the body of the microwave positioner into the target tissue; connecting the two or more microwave energy delivery devices to a microwave energy source; ablating the target tissue by delivering microwave energy through the microwave energy delivery devices and cooling the patient's tissue by providing airflow through a plurality of airflow apertures formed through the microwave positioner.
Two or more microwave positioners may be configured to connect and form an interlocking microwave spacer. Spacers may be daisy-chained together or may be grouped together in a specific pattern. The connection between microwave positioners may be accomplished by connection points formed on the microwave positioners or may be accomplished by utilizing a linking connector that is configured to link the two or more microwave positioners. In one embodiment, connecting the two or more microwave positioners positions a set of apertures to form a resection line.
While several embodiments of the disclosure have been shown in the drawings and/or discussed herein, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

## Claims

1. An energy delivery device positioner, comprising:
a body having a plurality of device positioner apertures defined therein, the body including a patient facing surface;
a plurality of legs coupled to the body, including at least one foot extending beyond the patient facing surface of the body, a distal end of the at least one foot configured to contact patient tissue;
a plurality of ribs forming the body and forming at least one air flow aperture through the body and between two or more of the plurality of ribs; and
wherein the plurality of device positioner apertures are configured to receive an energy delivery device therethrough and wherein the at least one foot elevates the patient facing surface of the body away from patient tissue.

2. The positioner according to claim 1, wherein the plurality of device positioner apertures further includes a first set of three device positioner apertures having radial centers equally spaced relative to one another.

3. The positioner according to claim 2, wherein the plurality of device positioner apertures further includes a second set of three device positioner apertures, the second set of three device positioner apertures being different than the first set of three device positioner apertures, the second set of three device positioner apertures having radial centers equally spaced relative to one another.

4. The positioner according to claim 3, wherein at least one aperture of the second set of three device positioner apertures is positioned about midways between two apertures of the first set of three device positioner apertures.

5. The positioner according to claim 1, wherein the plurality of legs includes three legs substantially equal in length.

6. The positioner according to claim 5, wherein the plurality of legs elevate the tissue facing surface of the body at least 0.5 inches relative to patient tissue.

7. The positioner according to claim 1, wherein the plurality of ribs are configured to provide structural rigidity.

8. The positioner according to claim 1, wherein the at least one air flow aperture includes at least three air flow apertures through the body, wherein each of the at least three air flow apertures is formed between the two or more of the plurality of ribs.

9. The positioner according to claim 1, wherein the plurality of device positioner apertures formed by the body are substantially parallel.

10. The system according to claim 1, wherein the plurality of ribs includes at least three ribs.